(Y05) Reintroduced the methods for using ImageData, since they?re already implemented and I have a very good usecase:
It?s useful for the tricks we need on mobile for fast application launch: Take a snapshot of the UI at application shutdown and display it on application start.
2 * Back 2 Browser Bytecode Translator Copyright (C) 2012 Jaroslav Tulach
3 * <jaroslav.tulach@apidesign.org>
5 * This program is free software: you can redistribute it and/or modify it under
6 * the terms of the GNU General Public License as published by the Free Software
7 * Foundation, version 2 of the License.
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
11 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
14 * You should have received a copy of the GNU General Public License along with
15 * this program. Look for COPYING file in the top folder. If not, see
16 * http://opensource.org/licenses/GPL-2.0.
18 package net.java.html.canvas;
21 import net.java.html.canvas.Style.Color;
22 import net.java.html.canvas.Style.LinearGradient;
23 import net.java.html.canvas.Style.Pattern;
24 import net.java.html.canvas.Style.RadialGradient;
25 import net.java.html.canvas.spi.GraphicsEnvironment;
26 import org.apidesign.html.canvas.impl.CnvsAccssr;
29 * A 2D Graphics Context similar to HTML5 or JavaFX GraphicsContext. Use this to
30 * paint on your Canvas
34 public final class GraphicsContext {
36 public static void init() {
37 // do nothing we need this in order to have the class loaded and static
38 // block executed for CnvsAccssr.
41 GraphicsEnvironment graphicsEnvironmentImpl;
44 CnvsAccssr cnvsAccssr = new CnvsAccssr() {
46 public GraphicsContext create(GraphicsEnvironment environment) {
47 return new GraphicsContext(environment);
52 GraphicsContext(GraphicsEnvironment graphicsEnvironment) {
53 this.graphicsEnvironmentImpl = graphicsEnvironment;
57 * Adds path elements to the current path to make an arc.
59 * @param centerX the center x position of the arc.
60 * @param centerY the center y position of the arc.
61 * @param startAngle the startAngle of the arc
62 * @param radius the radius of the arc.
63 * @param endAngle the endAngle of the arc
64 * @param ccw the direction of the arc (counterclockwise)
66 public void arc(double centerX,
72 graphicsEnvironmentImpl.arc(centerX, centerY, startAngle, radius, endAngle, ccw);
76 * Adds segments to the current path to make an arc.
78 * @param x1 the X coordinate of the first point of the arc.
79 * @param y1 the Y coordinate of the first point of the arc.
80 * @param x2 the X coordinate of the second point of the arc.
81 * @param y2 the Y coordinate of the second point of the arc.
82 * @param radius the radius of the arc in the range {0.0-positive infinity}.
84 public void arcTo(double x1,
89 graphicsEnvironmentImpl.arcTo(x1, y1, x2, y2, radius);
93 * Returns true if the the given x,y point is inside the path.
95 * @param x the X coordinate to use for the check.
96 * @param y the Y coordinate to use for the check.
97 * @return true if the point given is inside the path, false otherwise.
99 public boolean isPointInPath(double x, double y) {
100 return graphicsEnvironmentImpl.isPointInPath(x, y);
104 * Fills the path with the current fill paint.
107 graphicsEnvironmentImpl.fill();
111 * Strokes the path with the current stroke paint.
113 public void stroke() {
114 graphicsEnvironmentImpl.stroke();
120 public void beginPath() {
121 graphicsEnvironmentImpl.beginPath();
127 public void closePath() {
128 graphicsEnvironmentImpl.closePath();
132 * Clips using the current path
135 graphicsEnvironmentImpl.clip();
139 * Issues a move command for the current path to the given x,y coordinate.
141 * @param x0 the X position for the move to command.
142 * @param y0 the Y position for the move to command.
144 public void moveTo(double x, double y) {
145 graphicsEnvironmentImpl.moveTo(x, y);
149 * Adds segments to the current path to make a line at the given x,y
152 * @param x1 the X coordinate of the ending point of the line.
153 * @param y1 the Y coordinate of the ending point of the line.
155 public void lineTo(double x, double y) {
156 graphicsEnvironmentImpl.lineTo(x, y);
160 * Adds segments to the current path to make a quadratic curve.
162 * @param cpx the X coordinate of the control point
163 * @param cpy the Y coordinate of the control point
164 * @param x the X coordinate of the end point
165 * @param y the Y coordinate of the end point
167 public void quadraticCurveTo(double cpx, double cpy, double x, double y) {
168 graphicsEnvironmentImpl.quadraticCurveTo(cpx, cpy, x, y);
172 * Adds segments to the current path to make a cubic bezier curve.
174 * @param cp1x the X coordinate of first bezier control point.
175 * @param cp1y the Y coordinate of the first bezier control point.
176 * @param cp2x the X coordinate of the second bezier control point.
177 * @param cp2y the Y coordinate of the second bezier control point.
178 * @param x the X coordinate of the end point.
179 * @param y the Y coordinate of the end point.
181 public void bezierCurveTo(double cp1x, double cp1y, double cp2x, double cp2y, double x, double y) {
182 graphicsEnvironmentImpl.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
186 * Fills a rectangle using the current fill paint.
188 * @param x the X position of the upper left corner of the rectangle.
189 * @param y the Y position of the upper left corner of the rectangle.
190 * @param width the width of the rectangle.
191 * @param height the height of the rectangle.
193 public void fillRect(double x, double y, double width, double height) {
194 graphicsEnvironmentImpl.fillRect(x, y, width, height);
198 * Strokes a rectangle using the current stroke paint.
200 * @param x the X position of the upper left corner of the rectangle.
201 * @param y the Y position of the upper left corner of the rectangle.
202 * @param width the width of the rectangle.
203 * @param height the height of the rectangle.
205 public void strokeRect(double x, double y, double width, double height) {
206 graphicsEnvironmentImpl.strokeRect(x, y, width, height);
210 * Clears a portion of the canvas with a transparent color value.
212 * @param x X position of the upper left corner of the rectangle.
213 * @param y Y position of the upper left corner of the rectangle.
214 * @param width width of the rectangle.
215 * @param height height of the rectangle.
217 public void clearRect(double x, double y, double width, double height) {
218 graphicsEnvironmentImpl.clearRect(x, y, width, height);
222 * Clears a portion of the canvas with a transparent color value.
224 * @param x X position of the upper left corner of the rectangle.
225 * @param y Y position of the upper left corner of the rectangle.
226 * @param width width of the rectangle.
227 * @param height height of the rectangle.
229 public void rect(double x, double y, double width, double height) {
230 graphicsEnvironmentImpl.rect(x, y, width, height);
234 * Saves the following attributes onto a stack.
236 * <li>Global Alpha</li>
237 * <li>Global Blend Operation</li>
239 * <li>Fill Paint</li>
240 * <li>Stroke Paint</li>
241 * <li>Line Width</li>
244 * <li>Miter Limit</li>
245 * <li>Number of Clip Paths</li>
247 * <li>Text Align</li>
248 * <li>Text Baseline</li>
252 * This method does NOT alter the current state in any way. Also, not that
253 * the current path is not saved.
256 graphicsEnvironmentImpl.save();
260 * Pops the state off of the stack, setting the following attributes to
261 * their value at the time when that state was pushed onto the stack. If the
262 * stack is empty then nothing is changed.
265 * <li>Global Alpha</li>
266 * <li>Global Blend Operation</li>
268 * <li>Fill Paint</li>
269 * <li>Stroke Paint</li>
270 * <li>Line Width</li>
273 * <li>Miter Limit</li>
274 * <li>Number of Clip Paths</li>
276 * <li>Text Align</li>
277 * <li>Text Baseline</li>
282 public void restore() {
283 graphicsEnvironmentImpl.restore();
287 * Rotates the current transform in degrees.
289 * @param angle value in degrees to rotate the current transform.
291 public void rotate(double angle) {
292 graphicsEnvironmentImpl.rotate(angle);
296 * Concatenates the input with the current transform.
298 * @param mxx - the X coordinate scaling element of the 3x4 matrix
299 * @param myx - the Y coordinate shearing element of the 3x4 matrix
300 * @param mxy - the X coordinate shearing element of the 3x4 matrix
301 * @param myy - the Y coordinate scaling element of the 3x4 matrix
302 * @param mxt - the X coordinate translation element of the 3x4 matrix
303 * @param myt - the Y coordinate translation element of the 3x4 matrix
305 public void transform(double mxx, double myx, double mxy, double myy, double mxt, double myt) {
306 graphicsEnvironmentImpl.transform(mxx, myx, mxy, myy, mxt, myt);
310 * Concatenates the input with the current transform.
312 * @param mxx - the X coordinate scaling element of the 3x4 matrix
313 * @param myx - the Y coordinate shearing element of the 3x4 matrix
314 * @param mxy - the X coordinate shearing element of the 3x4 matrix
315 * @param myy - the Y coordinate scaling element of the 3x4 matrix
316 * @param mxt - the X coordinate translation element of the 3x4 matrix
317 * @param myt - the Y coordinate translation element of the 3x4 matrix
319 public void setTransform(double mxx, double myx, double mxy, double myy, double mxt, double myt) {
320 graphicsEnvironmentImpl.setTransform(mxx, myx, mxy, myy, mxt, myt);
324 * Translates the current transform by x, y.
326 * @param x value to translate along the x axis.
327 * @param y value to translate along the y axis.
329 public void translate(double x, double y) {
330 graphicsEnvironmentImpl.translate(x, y);
334 * Scales the current transform by x, y.
336 * @param x value to scale in the x axis.
337 * @param y value to scale in the y axis.
339 public void scale(double x, double y) {
340 graphicsEnvironmentImpl.scale(x, y);
344 * Draws an image at the given x, y position using the width and height of
347 * @param image the image to be drawn.
348 * @param x the X coordinate on the destination for the upper left of the
350 * @param y the Y coordinate on the destination for the upper left of the
353 public void drawImage(Image image, double x, double y) {
354 Object nativeImage = graphicsEnvironmentImpl.drawImage(image, x, y, image.getCached());
355 image.cache(nativeImage);
359 * Draws an image into the given destination rectangle of the canvas. The
360 * Image is scaled to fit into the destination rectagnle.
362 * @param image the image to be drawn.
363 * @param x the X coordinate on the destination for the upper left of the
365 * @param y the Y coordinate on the destination for the upper left of the
367 * @param width the width of the destination rectangle.
368 * @param height the height of the destination rectangle.
370 public void drawImage(Image image, double x, double y, double width, double height) {
371 Object nativeImage = graphicsEnvironmentImpl.drawImage(image, x, y, width, height, image.getCached());
372 image.cache(nativeImage);
376 * Draws the current source rectangle of the given image to the given
377 * destination rectangle of the Canvas.
379 * @param image the image to be drawn.
380 * @param sx the source rectangle's X coordinate position.
381 * @param sy the source rectangle's Y coordinate position.
382 * @param sw the source rectangle's width.
383 * @param sh the source rectangle's height.
384 * @param dx the destination rectangle's X coordinate position.
385 * @param dy the destination rectangle's Y coordinate position.
386 * @param dw the destination rectangle's width.
387 * @param dh the destination rectangle's height.
389 public void drawImage(Image image, double sx, double sy, double sw, double sh, double dx, double dy, double dw, double dh) {
390 Object nativeImage = graphicsEnvironmentImpl.drawImage(image, sx, sy, sw, sh, dx, dy, dw, dh, image.getCached());
391 image.cache(nativeImage);
395 * Merges two images drawing one on top of the other and returning the
398 * @param a the lower Image
399 * @param b the upper Image
402 public Image merge(Image a, Image b) {
403 if (a.getCached() == null) {
406 if (b.getCached() == null) {
409 Object nativeImage = graphicsEnvironmentImpl.mergeImages(a, b, a.getCached(), b.getCached());
410 Image merged = Image.create("should add real path here");
411 merged.cache(nativeImage);
415 // public void setShadowColor(String color) {
416 // graphicsEnvironmentImpl.setShadowColor(color);
419 // public void setShadowBlur(double blur) {
420 // graphicsEnvironmentImpl.setShadowBlur(blur);
423 // public void setShadowOffsetX(double x) {
424 // graphicsEnvironmentImpl.setShadowOffsetX(x);
427 // public void setShadowOffsetY(double y) {
428 // graphicsEnvironmentImpl.setShadowOffsetY(y);
431 // public String getShadowColor() {
432 // return graphicsEnvironmentImpl.getShadowColor();
435 // public double getShadowBlur() {
436 // return graphicsEnvironmentImpl.getShadowBlur();
439 // public double getShadowOffsetX() {
440 // return graphicsEnvironmentImpl.getShadowOffsetX();
443 // public double getShadowOffsetY() {
444 // return graphicsEnvironmentImpl.getShadowOffsetY();
448 * Gets the current stroke line cap attribute.
450 * @return a value of butt, round, or square.
452 public String getLineCap() {
453 return graphicsEnvironmentImpl.getLineCap();
457 * Sets the current stroke line cap attribute.
459 * @param style a value of miter, bevel, or round.
461 public void setLineCap(String style) {
462 graphicsEnvironmentImpl.setLineCap(style);
466 * Gets the current stroke line join attribute.
468 * @return a value of miter, bevel, or round.
470 public String getLineJoin() {
471 return graphicsEnvironmentImpl.getLineJoin();
475 * Sets the current stroke line join attribute.
477 * @param style a value of miter, bevel, or
480 public void setLineJoin(String style) {
481 graphicsEnvironmentImpl.setLineJoin(style);
485 * Gets the current line width attribute.
487 * @return value between 0 and infinity, with any other value being ignored
488 * and leaving the value unchanged.
491 public double getLineWidth() {
492 return graphicsEnvironmentImpl.getLineWidth();
496 * Sets the current line width attribute.
498 * @param lw value between 0 and infinity, with any other value being
499 * ignored and leaving the value unchanged.
502 public void setLineWidth(double width) {
503 graphicsEnvironmentImpl.setLineWidth(width);
507 * Gets the current miter limit attribute.
509 * @return limit value between 0 and positive infinity with any other value
510 * being ignored and leaving the value unchanged.
512 public double getMiterLimit() {
513 return graphicsEnvironmentImpl.getMiterLimit();
517 * Sets the current miter limit attribute.
519 * @param ml miter limit value between 0 and positive infinity with any
520 * other value being ignored and leaving the value unchanged.
522 public void setMiterLimit(double limit) {
523 graphicsEnvironmentImpl.setMiterLimit(limit);
527 * Sets the fill style. Will be used when rendering something, e.g. calling
528 * one of the fillText Methods.
532 public void setFillStyle(Style style) {
533 Object nativeFillStyle = graphicsEnvironmentImpl.setFillStyle(style, style.getCached());
534 style.cache(nativeFillStyle);
538 * get the current font
540 * @return current Font. of the fillText Methods.
542 public String getFont() {
543 return graphicsEnvironmentImpl.getFont();
547 * Set the Font. Will be used when rendering Text, e.g. by calling one of
548 * the fillText Methods.
552 public void setFont(String font) {
553 graphicsEnvironmentImpl.setFont(font);
557 * sets the Style of the Stroke.
561 public void setStrokeStyle(Style style) {
562 Object nativeStrokeStyle = graphicsEnvironmentImpl.setStrokeStyle(style, style.getCached());
563 style.cache(nativeStrokeStyle);
567 * Gets the current TextAlignment attribute
569 * @return TextAlignment with values of left, center, right, or justify.
571 public String getTextAlign() {
572 return graphicsEnvironmentImpl.getTextAlign();
576 * Defines horizontal text alignment, relative to the text {@code x} origin.
578 * Let horizontal bounds represent the logical width of a single line of
579 * text. Where each line of text has a separate horizontal bounds.
581 * Then TextAlignment is specified as:
583 * <li>left: the left edge of the horizontal bounds will be at {@code x}.
584 * <li>center: the center, halfway between left and right edge, of the
585 * horizontal bounds will be at {@code x}.
586 * <li>right: the right edge of the horizontal bounds will be at {@code x}.
590 * Note: Canvas does not support line wrapping, therefore the text alignment
591 * Justify is identical to left aligned text.
594 * @param textAlign with values of left, center, right.
596 public void setTextAlign(String textAlign) {
597 graphicsEnvironmentImpl.setTextAlign(textAlign);
601 * Gets the current Text Baseline attribute.
603 * @return baseline with values of top, center, baseline, or bottom
605 public String getTextBaseline() {
606 return graphicsEnvironmentImpl.getTextBaseline();
610 * Sets the current Text Baseline attribute.
612 * @param baseline with values of top, center, baseline, or bottom
614 public void setTextBaseline(String textbaseline) {
615 graphicsEnvironmentImpl.setTextBaseline(textbaseline);
619 * Renders the indicated String with current fill. default is black.
621 * @param text the text to stroke
622 * @param x x coordinate of start position
623 * @param y y coordinate of start position
625 public void fillText(String text, double x, double y) {
626 graphicsEnvironmentImpl.fillText(text, x, y);
630 * Renders the indicated String with current fill. default is black.
632 * @param text the text to stroke
633 * @param x x coordinate of start position
634 * @param y y coordinate of start position
635 * @param maxWidth maximum width of text
637 public void fillText(String text, double x, double y, double maxWidth) {
638 graphicsEnvironmentImpl.fillText(text, x, y, maxWidth);
642 * Check the length of a text before writing it to the Canvas. Takes into
643 * account the current Font.
645 * @param text the text to measure
646 * @return the length in pixels
648 public Dimension measureText(String text) {
649 return graphicsEnvironmentImpl.measureText(text);
653 * Renders the indicated String (with no fill)
655 * @param text the text to stroke
656 * @param x x coordinate of start position
657 * @param y y coordinate of start position
659 public void strokeText(String text, double x, double y) {
660 graphicsEnvironmentImpl.strokeText(text, x, y);
664 * Renders the indicated String (with no fill)
666 * @param text the text to stroke
667 * @param x x coordinate of start position
668 * @param y y coordinate of start position
669 * @param maxWidth maximum width of text
671 public void strokeText(String text, double x, double y, double maxWidth) {
672 graphicsEnvironmentImpl.strokeText(text, x, y, maxWidth);
675 public ImageData createPixelMap(double x, double y) {
676 return graphicsEnvironmentImpl.createPixelMap(x, y);
679 public ImageData createPixelMap(ImageData pixelMap) {
680 return graphicsEnvironmentImpl.createPixelMap(pixelMap);
683 public ImageData getSnapshot(double x, double y, double width, double height) {
684 return graphicsEnvironmentImpl.getPixelMap(x, y, width, height);
687 public void drawPixelMap(ImageData pixelMap, double x, double y) {
688 graphicsEnvironmentImpl.putPixelMap(pixelMap, x, y);
691 public void drawPixelMap(ImageData pixelMap, double x, double y, double dirtyx, double dirtyy, double dirtywidth, double dirtyheight) {
692 graphicsEnvironmentImpl.putPixelMap(pixelMap, x, y, dirtyx, dirtyy, dirtywidth, dirtyheight);
695 * Sets the global alpha of the current state.
697 * @param alpha value in the range {@code 0.0-1.0}. The value is clamped if
698 * it is out of range.
700 public void setGlobalAlpha(double alpha) {
701 graphicsEnvironmentImpl.setGlobalAlpha(alpha);
705 * Gets the current global alpha.
707 * @return the current global alpha.
709 public double getGlobalAlpha() {
710 return graphicsEnvironmentImpl.getGlobalAlpha();
714 * Sets the global blend mode.
716 * @param op the BlendMode that will be set.
718 public void setGlobalCompositeOperation(String operation) {
719 graphicsEnvironmentImpl.setGlobalCompositeOperation(operation);
723 * Gets the global blend mode.
725 * @return the global BlendMode of the current state.
727 public String getGlobalCompositeOperation() {
728 return graphicsEnvironmentImpl.getGlobalCompositeOperation();
732 * Create a LinearGradient to use in Canvas.
734 * @param x0 x coordinate of start point
735 * @param y0 y coordinate of start point
736 * @param x1 x coordinate of end point
737 * @param y1 y coordinate of end point
738 * @return the gradient
740 public LinearGradient createLinearGradient(double x0, double y0, double x1, double y1, Map<Double, String> stops) {
741 return Style.LinearGradient.create(x0, y0, x1, y1, stops);
745 * Create an Image Pattern from a source Image and a repeat style. Possible
746 * Styles are repeat, repeat-x, repeat-y, or no-repeat. defaults to repeat
748 * @param image the Image
749 * @param repeat the repeat style
750 * @return the Pattern
752 public Pattern createPattern(Image image, String repeat) {
753 return new Pattern(image, repeat);
757 * Create a RadialGradient
759 * @param x0 x Coordinate of starting circle
760 * @param y0 y Coordinate of starting circle
761 * @param r0 radius of starting circle
762 * @param x1 x coordinate of ending circle
763 * @param y1 y coordinate of ending circle
764 * @param r1 radius of ending circle
765 * @return the Gradient
767 public RadialGradient createRadialGradient(double x0, double y0, double r0, double x1, double y1, double r1, Map<Double, String> stops) {
768 return RadialGradient.create(x0, y0, r0, x1, y1, r1, stops);
772 * Convert this String Representation of a Color to a Color Object.
775 * @return The Color represented by the input
777 public Color getWebColor(String webColor) {
778 return new Style.Color(webColor);
782 * Get the height of this GraphicsContext (which should be the same as the
783 * enclosing canvas height)
785 * @return the height of this GraphicsContext
787 public int getHeight() {
788 return graphicsEnvironmentImpl.getHeight();
792 * Get the width of this GraphicsContext (which should be the same as the
793 * enclosing canvas height)
795 * @return the width of this GraphicsContext
797 public int getWidth() {
798 return graphicsEnvironmentImpl.getWidth();
801 // public void setHeight(int height) {
802 // graphicsEnvironmentImpl.setHeight(height);
805 // public void setWidth(int width) {
806 // graphicsEnvironmentImpl.setWidth(width);
809 * Fill a circle with a center position of centerX, centerY and the
816 public void fillCircle(float centerX, float centerY, float radius) {
817 graphicsEnvironmentImpl.arc(centerX, centerY, radius, 0, Math.PI * 2, false);
821 * Fills a polygon with the given points using the currently set fill paint.
823 * @param x_coord array containing the x coordinates of the polygon's
825 * @param y_coord array containing the y coordinates of the polygon's
827 * @param vertexCount the number of points that make the polygon.
829 public void fillPolygon(double[] x_coord, double[] y_coord, int vertexCount) {
830 if (vertexCount >= 1 && x_coord != null && x_coord.length >= vertexCount && y_coord != null && y_coord.length >= vertexCount) {
831 graphicsEnvironmentImpl.beginPath();
833 graphicsEnvironmentImpl.moveTo(x_coord[0], y_coord[0]);
834 for (int i = 1; i < vertexCount; i++) {
835 graphicsEnvironmentImpl.lineTo(x_coord[i], y_coord[i]);
838 graphicsEnvironmentImpl.closePath();
839 graphicsEnvironmentImpl.fill();
840 graphicsEnvironmentImpl.stroke();